Method of facilitating and accelerating the hardening of hydraulic cements.



. gary, residin pire of Austria-Hungary, have mventedcer- UN ITED STATES PATENT OFFICE.

LUDWIG HATSCHEK, OFVOCKLABRUCK, ATU STBIAFHUNGAB-Y.

METHOD OF FACILITATING AND. ACCELERATING THE HARDENING OF HYDRAULIC GEMENTS.

974,138. Specification of Letters Patent.

, No Drawing. 7

To all whom it may concern." Be it known that I,,LUDwIe HATSCHEK, a

subject of the Emperor of Austria-Hunat Vocklabruck, in, the: Em

tain new and usefuk Improvements in. Methods of Facilitating and Accelerating the Hardening of Hydraulic Cements; and.I do hereby declare the following tobe a full,

10 clear, and exact; description, of the: invention,

such as will enable others skilled in the art to which it appertains to makeand use the same.

The object. of this invention is to facilitate and accelerate the hardening of hydraulic cements in the course of the drying out thereof.

In the course of the manufacture of artificial stone employing hydraulic cement, according to an invention of mine, in which the cement is, first, swelled up or pulped, and rendered adhesive, by treatment with a great bulk of water as set forth in my Reissue Patent No. 12,594, and, then, ut up in layers, when there are layers su cient to afford the desired thickness, the mass, thus produced, and in the form of a slab is, with others of its kind, stacked in a press with a metallic plate between every two slabs, and

pressed, after which, the stack is taken out and placed apart for the slabs to set and harden. U on removal from the press, the slabs are, 0? course, hot, and are still moist. In the hardening, heat and moisture are necessary to insure good results, and, as the plates conduct away the heat, and the moisture becomes dissi ated, heat and moisture have been supplie tion of steam. Not only, however, does this 40 involve a separate and circumstantial operaextraneously by adduc- Patented Nov. 1, 1910;

Application.filedfiecember 17, 1909.. Serial No. 538,575..

tion,;but the supply off steam apt to cause efliorescence, or; spotting, and blistering of the product, probably from dissolving out of'lime by superabundant moisture and unequal heating of. the plates. I overcome: the,

difficulty by placing the slabs, after pressing,

in a close, or hermetically sealed chamber, boa,v or vessel, whereby the heat is com served, and the slabs, themselves, supply, au-- tomatically, the; requisite moisture. Theheat may, favorably, be held at 100 to- 120 F., inoreorless, as requisite. By this operation, not only is the procedure of, hardeningfacilitated, but the hardening is greatly accelerated, a result which it may require 4 weeks to bring about, sometimes being achieved in 24 hours; and not only is the product devoid of efilorescence, or spots, but-there is no sticking of the cement to the plates, which are then readily removed, leaving an unblistered and smooth surface.

Having, thus, fully described my invention, what I claim and desire to secure by LUDW'I'G HATSCHEK.

Witnesses:

R. G. DYRENFORTH, H. T. Wnnnmmenn. 

